Method of operation for reducing power, increasing life and improving performance of epids

Abstract

Method for operating an electrophoretic display panel in a hold mode that reduces power required , increases display life and improves performance which entails applying a voltage to the anode electrode structure during the "hold" mode of operation which is substantially lower in amplitude than the voltage applied to the anode structure during a "write" mode of operation.

What is claimed is: 
     
       1. A method for reducing the power composition of an electrophoretic display in a hold mode having an anode electrode and grid and cathode electrodes at least two of said electrodes forming an X-Y matrix comprising the steps of: applying a positive voltage to the anode electrode which voltage is at least 50 times less than the voltage applied to said anode electrode during a write mode of said display; and   operating the grid electrodes of said display at a negative potential with respect to the cathode electrodes of said display.   
     
     
       2. The method for operating an electrophoretic display panel according to claim 1 wherein the positive voltage applied has an value in the range between positive 1.5 and 3.0 volts. 
     
     
       3. The method according to claim 1 wherein said electrophoretic display further includes a mesh electrode and applying said positive voltage to said mesh electrode during said hold mode. 
     
     
       4. The method according to claim 3 further including the step of applying an AC voltage to said mesh electrode of a magnitude and frequency to remove pigment particles from said mesh. 
     
     
       5. The method according to claim 4 wherein said AC voltage has a magnitude of 100 vrms and a frequency of 60 Hz. 
     
     
       6. The method according to claim 5 wherein said AC voltage is applied to said mesh for a period of about 100 milliseconds. 
     
     
       7. The method according to claim 6 wherein said AC voltage is applied to said mesh during a "write" mode. 
     
     
       8. The method according to claim 6 wherein said AC voltage is applied to said mesh after a "write" mode.